1. Field of the Invention
The present invention relates to an information processing apparatus, a disk, an information processing method, and a program and, in particular to, an information processing apparatus, a disk, an information processing method, and a program that control usage of content recorded in an information recording medium.
2. Description of the Related Art
In order to record content, disks, such as a digital versatile discs (DVD) and Blu-ray Discs (trade name) have been used as recording media. For example, movie content is recorded in a disk (e.g., a ROM disk) and provided to a user. In many cases, the copyright and distribution rights of the content are owned by the author and the seller. For example, in order to protect the content against unauthorized copying, the use of the content is restricted.
An advanced access control system (AACS) has been developed as a copyright management system. Content recorded on the disk that complies with such a copyright management system is recorded in the form of encrypted data written on a unit-by-unit basis. When reproducing content recorded on a disk, an information processing apparatus decrypts the content using a unit key provided for each of the units. Such a recording and reproduction method for encrypted content is described in, for example, Japanese Unexamined Patent Application Publication No. 2006-72688.
In order to provide more strict use of content, a control method in which a variety of types of identification information (ID) is used when content is reproduced has been developed. In this method, upon reproducing content, an information processing apparatus acquires an ID associated with a disk, an apparatus, and the content. Thereafter, the information processing apparatus verifies the ID and generates a key using the ID.
For example, a disk has the following identification information (IDs) recorded therein:
(a) a media ID which is unique to the disk (also referred to as a pre-recorded media serial number (PMSN)),
(b) a volume ID which is set on a title-by-title basis, and
(c) a content certification ID which is identification information of the content certificate provided to content recorded on a disk.
A reproduction apparatus reads at least one of the above-described identification information (IDs (a) to (c)) and performs processing in a predetermined sequence, for example, key generation and content decryption. Thus, the content can be used. In addition, the reproduction apparatus may send the identification information (IDs) to a server. After the server verifies the IDs, the reproduction apparatus may receive various additional content and service data from the server.
By using such ID information and allowing the content to be reproduced only when a predetermined ID is used, disks or apparatuses that use the content can be limited.
However, if, for example, unauthorized IDs are recorded on disks in a disk manufacturing plant, the disks having the unauthorized IDs thereon are distributed. Therefore, content may be illegally used.